This project examines how the prosodic structure of language shapes the articulation of spoken utterances. Speaking is a complex, uniquely human ability that relies on precisely coordinated movements of the speech organs (tongue, lips, jaw, soft palate, and larynx) and respiratory system. These movements produce sounds that listeners perceive and that convey not only the 'dictionary' content of the utterance, but also its prosodic content. Prosody organizes phonological forms into successively larger units or phrases, and renders certain syllables, words and phrases more 'prominent' (perceptually or rhythmically important) to the listener. Understanding the processes that shape prosodic structure and how these processes act to transmit this structure through coordination of the speech organs has profound implications for advancing our understanding of language processing and communication disorders, for improving speech technology, and for providing insights regarding the more general relationship between linguistic and cognitive operations. The central hypothesis examined in this collaborative project is that the control processes governing temporal and tonal structure are intimately linked with one another. This linkage is viewed as emerging from the underlying motor control dynamics that coordinate the motions of the speech organs and guide speech production. In order to investigate this hypothesis, two additional open questions are addressed concerning the nature of the units that exist at different prosodic and prominence levels, and the relationships among syllables, prosodic feet, words and phrases: "What are the structural and articulatory-acoustic properties of prosodic feet?"; and "How can the relationships among the levels be best understood?" These questions are investigated through a series of articulatory studies--using electromagnetic articulography--and acoustic measurements that will examine: 1) how temporal and tonal properties interact at phrasal boundaries, 2) how temporal and tonal properties interact within and across all levels of prominence, and 3) how motor control dynamics shape the details of articulatory-acoustic structure at the foot level. These studies will be complemented by a series of computational simulations, which will serve the dual purpose of testing the project's hypotheses and guiding further developments of the prosodic component of the group's Task-Dynamics model of speech production.